Question

oxygen is acting as an oxidizing agent in all of the following reactions excepta.
2 c(s) + o₂(g) → 2 co(g)
b.
s(s) + o₂(g) → so₂(g)
c.
2 f₂(g) + o₂(g) → 2 of₂(g)
d.
2 na(s) + o₂(g) → na₂o₂(s)
e.
2 mg(s) + o₂(g) → 2 mgo(s)

Explanation:

To determine in which reaction oxygen is not an oxidizing agent, we analyze the oxidation states of oxygen:

• In an oxidizing agent, the element (oxygen here) gains electrons, so its oxidation state decreases (is reduced).
• Option A: In \(O_2\) (oxidation state = 0), in \(CO\), O has oxidation state -2. O is reduced (oxidizing agent).
• Option B: In \(O_2\) (0), in \(SO_2\), O is -2. O is reduced (oxidizing agent).
• Option C: In \(O_2\) (0), in \(OF_2\), O has oxidation state +2 (since F is -1, and \(2\times(-1) + x = 0\) → \(x = +2\)). Here, O is oxidized (loses electrons, oxidation state increases from 0 to +2), so \(O_2\) is acting as a reducing agent, not an oxidizing agent.
• Option D: In \(O_2\) (0), in \(Na_2O_2\), O has oxidation state -1. O is reduced (oxidizing agent).
• Option E: In \(O_2\) (0), in \(MgO\), O is -2. O is reduced (oxidizing agent).

Answer:

C. \(2 F_2(g) + O_2(g)
ightarrow 2 OF_2(g)\)